block subscriber from viewing the whole library

hello friend

I need to block subscribers from viewing the whole library when ther are posting on my website, I found the following code for

functions.php

//Remove Media Library Tab
function remove_medialibrary_tab($tabs) {
if ( !current_user_can( ‘administrator’ ) ) {
unset($tabs[‘library’]);
return $tabs;
}
else
{
return $tabs;
}
}
add_filter(‘media_upload_tabs’,’remove_medialibrary_tab’);

I am writing you to ask whether there is easier way through CSS which will do the same function for this theme? if where should I exactly place this code in functions.php?

thanks in advance